Frederick Ronald Cohen[1] (1945 – January 16, 2022)[2][3] was an American mathematician working in algebraic topology.

[2][4] Cohen did influential work in several areas of homotopy theory.

This was followed by a series of influential papers on unstable homotopy groups of spheres with John Moore and Joseph Neisendorfer.

[5] Late in his life, Cohen studied polyhedral products in a series of articles with Bahri, Bendersky, and Gitler.

Although he survived with the help of radiation therapy, he was partially paralyzed for the rest of his life.